1. Technical Field
The invention relates to a method and an apparatus for processing audio signals, and particularly relates to a method and an apparatus for detecting noise of audio signals.
2. Related Art
Generally, when audio signals of voice or music are processed, a background noise in the audio signals is first detected. The background noise is also referred to as messy noise or white noise, which is unnecessary noise and required to be removed from the audio signals. There are three solutions for estimating the white noise.
A first solution is to track a signal strength of the audio signal by calculation of moving average, and then estimate the noise in the audio signal according to a change of energy magnitude. However, such method cannot estimate noise energy in real-time, and if the noise is varied dramatically, an estimating result is probably inaccurate. A second solution is to use entropy statistics, though a computation amount of such method is huge, and a time length of the statistics may influence the accuracy of the noise estimation, and is hard to be determined. A third solution is to use a model comparison, though accuracy of an estimation result thereof is highly correlated to a voice training material, such that the estimation result of the noise is hard to be controlled.